1. Field of the Invention
The present invention relates generally to switching power converters.
2. Description of the Related Art
Switched-mode voltage converters provide superior power conversion efficiency because they regulate an output voltage or output current with transistor switches that are either on or off so that they never operate in the linear region in which both current and voltage are nonzero. Because at least one of transistor current and voltage is therefore always close to zero, power dissipation is greatly reduced. Because of their high efficiencies, switching converters have been found to be particularly useful in a variety of portable devices (e.g., mobile phones, digital cameras, digital radios, portable disk drives and media players) that are powered by internal batteries (e.g., lithium batteries).
Feedback control in these converters has typically been accomplished with analog circuits that generally have performance-limiting characteristics, e.g., low bandwidth, high power consumption, and parameter degradation over temperature. Accordingly, the performance of conventional feedback controls has been found to be a limiting element in modern switching converter systems.